I watched the Tsukihime anime back when it aired, and I rewatched it after playing the english translation when it was released.
I still really like the anime. The atmosphere is the show is perfect, and the music is fuckwin. There's some slight changes to the characterization (which was no big deal really) and I still BAWWWWWed at the end of the show.
Because of that I consider it a decent adapation. Tsukihime itself is a BAWWWWWing romance tragedy series, afterall.